Means for recording sound waves



-J. MASSQLLzE `E'I'Al.

MEANS FOR RECORDING SOUND WAVES 'INVENTORSz Qvroeneys J. MAssoLLE 5TM. l

MEANS' Fon RECORDING Suw ymvs Filed April 4, 1921 2. Sheets-Sheet 2 FIG. 5

A' Sq. f I fr v so L v I 52 Y 53 V.lnlvenorezr Jos EPH Massa/f HA NsV067 (/oEF Eis/6l.

Patented Dec. 22, 19.9.5.`

unirse srares Partnr oir-Fica JGSEIE'I-I lVf-IASSOLLE AND-JDSEF ENGL. OFGRUNEVALD, AND HANS VQGT, OF BEHLN- SCHNEBERG, GERMANY,'ASSIGNORS T0TR-ERGON LIIVTED, 0F ZURGH, SW'T- ZEELAND.

Application filed April 4, m21.

To GU10/10m if. may concer-14 lie it linown that we, losnru Massomni,.loser Thun, and l-lANs Your, citizens of the German Republic, residing.the first and second at Grunewald. the third at Berlin-Schoneberg,Germany, have invented certain new and useful Improvements in Means forRecording/Sound lYaves, of which the following is a specification.

lu the recording of sound waves it is necessary, for example for opticalacoustical operations (speaking film, granuuihonetic musicalperformances, acoustic advertisements. and the like) to fix the soundw'aves in order to be'able to utilize the recorded symbols forreproduction.

This invention relates to an arrangement for recordingsound waves inwhich the fixation on a moving film is effected photographically in sucha manner that the lsound waves act on a pencil of light raysinaccordance with their .frequency and intensity.

l'ior this purpose the arangrement is so constructed that the energy ofthe sound is coinpressed and acts on a mirror mounted on one side. Thismirror i. e., a diaphragm having a light-reliectine' surface, haspreferably a high individual frequency 'and is of small dimensions sothatsa maximum impressionability and great angle of rotation areobtained.

The invention may be practiced by the use of one reflecting;` diaphragm,or of several reflecting' diaphragma/against which the sound waves willimpinge and from the reflecting; surfaces of which light rays will berefiected. These reflected rays will be utilixed. for example, byrecordingy the varying innige photographically ou a sensitized ihn, alvrecord thereby being' formed which corresponds to the. variations of theorigina-l sound Waves.

With diaphragnis secured at one edge only, various advantages aresecured. Thus,

a minimum of poweris required to obtain a desired movement of thediaphragm; a

smaller diaphragm may be used to produce the same deflection, than witha diaphragm otherwise z uounted, injith the same'erertion Sera No.458,633.

ot' power upon it; and the light rays reflected from the reflecting'diaphragm vmay be kept parallel, with each other, because the diaphragmremains plane upon deflection, in

contradistinction to a diaphragm supportedO lVhen a plurality ofreiiecting diaphragms are used, they preferably have differentindividual natural rates of vibration, so chosen that they willreinforce sounds re"eived 'by the diaphragme throughout a Wide range lheconstruction also 1s preferably such that ay damping effect is obtainedat the da` phragrms. Accordingly the recorded curve would have variousresonance peaks, corresponding to the tones and overtones to which thevarious diaphragms respond, but for the fact that these peaks aresomewhat iiattened hy the damping effect, whereby the resultantcurve-more corre tly corresponds to the original sound Vibrations.

The invention, in addition to its use for recording sound on sensitizedsurfaces, etc., may be utilized for other purposes, as for example, forcausingthe acoustioallycontrolled light to control the internalresistance of a light-sensitive cell.

The invention consists in arangements and combinations in acordance withthe foregoing, all as will be more fully described hereinafter andparticularly pointed out in the appended claims.

In order that the invention may be more clearly understood, attention ishereby directed to the accompanying drawings, forming part of thisapplication, and illustrating; certainembodiments of the invention. Inthe drawings, i i

Fig. l is a diagrammatic sectional view illustrating the use of a singlereflecting diaphragm g Fig. 2 is a similar View, showing two refiectingdiaphragms jointly covering the open ing; y

l- Fig. 3 is adiagrannnatic, parti-afl, enlarged through a modified tormot apparatus 'in which a plurality of reflecting diaphragme are usedsi'iccessively; and

Fig. 7 is a view similar to that of Fig'. #12, but showing alight-sensitive cell in place of the sensitized film, to receive theacoustically-varied light.

The invention may be carried out. tor cte ample by causing` a collectingdevice 0 (sound horn see Fig. 4') which embraces great angular ranges toconcentrate the energy ot' the sound on a reflecting diaphragm s1. Thisdiaphragm is for example of rec tmgular form and is clamped tast on oneside as shown b v way ot' example in Fig.' l. lt practically completelycovers the orifice oft' the collectingl device O. The dimensions ot thediaphragm al are preferably such that the highest possible individualtrequency is ensured and that, owing to the small mass ot' the diaphragmaV pcrceivable deflection is secured even with small sound energy. An

individual frequency may be used (e. g. ot' 'i2000 to 15000) which liesbeyond the t'requencies usual in ordinary sound operations.

'The invention may also be carried out so that, instead otl the smallmirror 31 several, tor example according to Fig. Q two mirrors ,al ands2 are used Which are mounted each at a point oi its circumferenceopposite the point ot the circumference at which the other mirror isfixed, so that they deflect, one, in the direction of a right handrotation, the other, in the direction of a left hand rotation. Theirdimensions are preferably so chosen that they possess differentindividual frequencies. It is ot advantage to frive the one diaphragmcomparatively low individual vibration so that it acts specially on theindividual vibrations of the vowels and their diphthongs. lts 'dampingis suitabl so chosen that the higher harmonics o its `ibrations will notcause a disturbing effect. '.lhis is effected for example by thesuitable choice of its distance from the attachment trame i' (sce Figs.l and The second rctlectif fr diaphragm is made of such dimensions, thatit reproduces the high frequency vibrations ot the consonants andsihilant rcfiecting surface of the diaphragm or mirror s1, Fig. l, orthe tvvov diaphragms 31 and s2, Fig. 2, and be reflected thereby, thereflected light being directed, for example, by a number ot' prisms p,to produce an image of the light source on a slit sp. The inner edges otthe two mirrors off Fig. 2 determine on the slit two limits g1, g2,(Fig. 3), between illuminated and unilluminated parts ot the, slit.Their distance apart can be fixed by tilting the surfaces ot the mirrorswith relation to each other.

According to the state ot movement of the diaphragme the limits of thelight displace themselves on the slit and efl'ect on a lm f, movingrapidly behind the slit, transverse blackenings ot ditlerent lengths.

ln order to increase the sensitiveuess ot the arrangement it` is furtherof advantage to prolong the path ot' the rays off light from thereflecting diaphragm to the slit through which the image is to beprojected. ln order, however, to avoid making the apparatus too long,the course ot the rays may be bent repeatedly by means ot totalreflecting prisms (p in liig. t.) or hy means of simple mirrors.

ln contradistinction trom the form of construction described thearrangement may also be made in such a manner that the light pencil isrcflei'ted successively by a plurality ot small retlecting diaphragrms,ot different individual frequencies whereby merely an area ofhlaekenings is produced on the film which shows the variations ot thelower frequencies and over it superposed in correct phase the highfrequencies. This form is described more fully hereinafter, inconnection with Fig. 6.

lll/'ith such devices tor recording;l sound Waves by optical means withthe aid of a pencil of light influenced h v the .sound energy,comparativelv small angular detlections of the oscillating' mirror mayhe advisable. l'n order however to obtain thus sufficient amplitudes otthe light pencil at the recordingV point. there hare heretofore beenused correspoudiugly long light pointers such as are used iu .similarmirror rccorders (mirror galvanometcr etal. For acoustical recordingrapparatus sacd ar- 5 for example may be of approximately cubical shape.

An example of constructional form of this :term or feature ot theinvention is oliagrai'i'i-A matically shown in the Fig. 5. The sound l@Waves, collected by the funnel shaped piece r, strilre on the reflectingdiaphragm 30. The pencil of rays emitted from a source of light l andconcentrated by the optical system on the small mirror Sm is caused by lthe oscillations of so to malte a transverse movement which is indicatedby the transverse arrow, continues in the direction indicated by thearronT and is reflected successively .by the mirrors si, e2, e3, s4. The

amplitudes ot' the ray of light which are rather large owing to thelongoptical path are then received upon the light sensitive strip f,Instead of the mirrors, other optical means may also be used for bendingthe path ot the light rays, e. e'. total reflection ,35 speaking, tivodetects.

prisms and the like. By the arrangement ot' the mirrors s1 to s* thenumber ot' which may naturally be smaller or greater, the dimensions otthe apparatus may be so selected 0 that it acquires a compact form treefrom w etc.) in which case this tact is manifested by a distortion of,the true values of inten sity otl the sound at all frequencies whichcoincide with the :fundamental tone of the vibrating' number or itsovertones. (lr the individual frequency ot the vibiatincY element isintentionally displaced beyond the. range ot the sound waves which areto be received in which casey no distortion can be detecteiil," but. theamplitudes of the oscillah ing element are comparatively small. rl`helatter way has heretofore not been practically realized. but it would heiulvantzigreoiis, in order to iii; sibilant sounds, 'lineness otconsonants`v etc. VY'Yitli such an :'u'rancemcnl, however, therecordingv oi the lower sound vibrations (vowel tones and diphthongs)would be insuilivicntly executed iu-corf'liugfly, in this invention.,iifdiii'elm t method is tol-I lowcd -which nature has' aire id vindicated in ,u .the human car. iever i elements are .l which are ableol :illal'i/.in and which arc consti as lo `torni reflecting easilyinliuenceci dii )l iig-fins ot the smallest pos- G s ile mass, therequirements et the registral 'tion of the' highestv frequency beingconi,-

plied with by the selection oit a correspond.- ingly higher individualfrequency of one o1 the small mirrors. The remaining reflectingdiaphragn'is are successively so selected that they possess suitablyditlerent individual oscillations in order to react strongly to voweltones etc. ln any case however for a reason above mentioned thedan'ipiugr ot the diapliragn'is must besuch that the above mentioneddesired ellect is counteracted to a sufiicient extent. On 'these smallmirrors, whose axes ot' rotation must be all parallel, there isreflected successively a pencil of' rays, which issues from a suitablesourcel of light and is concentrated by an optical system on the planewhere the recording takes place. The oscillating movement ot each ot'the small mirrors is transn'iittcd to the pencil of light. The smallmirrors themselves are all mounted next to one another at one locationin the space in order to allow the sound vibrations to act on all themirrors in` one and the same phase.

Fig. 6 shows diagrammatically by Way ot example a practical constructionot' the apparatus.- Gn the bottom u of the sound conductor t diaphragmssl s2, s are mounted which possess different. individual natural ratesof vibration and are all provided with;

reflecting surfaces. the diaphragms all being attached at one side only.By means of a source of light and of an optical system 0 a'pencil otparallel rays is thrown succesw sively with the aid of reflectors r1,'r2 on to the oscillatingsmall mirrors. The suitably controlled ray thenacts upon the plane e which represents a light sensitive film or` il'the oscillations are to be also electrically inY tensiiied, which may bea selenium or photoelectric cell. In the latter case the rays ol lichtmay imping'e against thel reflecting diaphragme simultaneously.

The dan'iiiing oit the diaphragmsmay be so arranged as to somewhatdecrease the sharpness of the resonance peaks in the acoustic llO curve.as stated. rlhis dampingl niay be ac# Y* inbeiiore 'been described couldalso he used At'or other technical purposes (Wireless telephony and thelike). 'this could he donc in all such cases where sound Waves have tobe transformed into electric oscillations or Where an acousticphenomenon has to be utilized electrically. la such cases a cell. whichis sensitive to radiation (e. g. a photoelectric alkaline metal cell orthe like (is employed, as shown in Fig. 7, for example). From theoscillating' mirrors of the acoustograph more or less light lis thrownin the rhythm vof the acoustic AWaves upon the photocell and variesrhythmically its electrical resistance. This tact can be utilized in themanner hcreinbefore described for controlling high frequencyoscillations or in any other convenient manner. The apparatus describedmight represent in connection with a high frequency circuit and With anantenna, a sender for wireless telephony.

l. ln acoustic apparatus, the combination ot' a fixed nieinber'having anorifice, a small diaphragm, covering saidorifice and attached to saidmember at one'side onlv, and having a reflecting surface. said diaphragmbeing adapted to be set in movement by sound waves impingring againstthe same, and means 'for directingr a ray of light upon the reflectingsurface of the diaphragm.

Q. ln acoustic apparatus, the combination of a sound collecting' devicehavingr an orifice, a diaphragm secured aty one side only andsubstantially coveringthe orice of said device` and having a refiectingsurface on the side opposite to that against which the sound wavesinipinge, means tor projecting a ray of light on the reiecting surfaceof the diaphragm, and means upon Which the reflected light falls.

3. ln acoustic apparatus, the combination of a supporting member. havingadjacent openings therein, a plurality of diaphragms covering saidopenings. exposed to sound waves on one side and havingA reflectingsurfaces on the other side, said diaphragms having: different individualfrequencies, a source tit-light. and means for directincf a beam oflight therefrom against the reflecting sur- `laces of each of saiddiaphragms in succession` and from the last ot said diaphrag'ms to adesired point.

4. ln acoustic apparatus, the combination ot a supporting member, a.plurality of small diaphrae'ms secured at one side onlv, exposed tosound ivaves on one side thereof and having' reflecting surfaces on theother side said diaphragms harina diti'erent individual frequencies. andmeans for directing light aoainst said reflecting surfaces to bereflected thereby. e

f. dcansA lor recording lsound wares coniprisingf a device t'ol'collecting' the SOlllld energy and condensing the same. and a smallrefiectine diaphragm possessing' high individual frequency. saiddiaphragm being attached at one side only and exposed to the action oi?condensed sound energy.

(l. Venus for recordingr soundtvaves. comprising a device forcollectingr the sound energy and condensing the same. and a plurality olthin and small reflecting dia- Vphragjlfn'is ixedly secured at one sideonly and exposed to the action of the condensed sound energy.

7. Means for recording sound Waves, com prising a device for-collectingthe sound energy and for condensing the same, and a plurality of smallreflecting diaphragme, possessing different individual frequencies, saiddiaphragms being rigidly attached at one side only and arranged so as tobe damped and exposed to the action of the condensed sound energy,whereby to record the structure of the lower vovvel vibrations and oftheir diphthongf and also the con sonantal sihilant sounds.

8. Means for recording sound waves comprising in combination with adevice for collecting the sound energy and lor condensing the same, aplurality of small rc- ,lecting diaphragms attached at one side onlyexposed tothe action of the condensed `sound energy. and a source oflight emitting a pencil ot light to be rctiected in succession by theseveral diaphragms so that the light pencil reflected from thediaphragms may make a record on a light sensitive band.

9. Means for recording sound Waves comrising in combination with adevice for col acting the sound energy and Jfor condensing the same, aplurality of small redecting diaphragms possessing dierent individualirequencies and rigidly attached at one side only and so as to be dampedand exposed to the action of the condensed. sound energia.

a source of light emitting a, pencil ot light to' be reflected linsuccession by the several diaphragms so that the light encil retlectedfrom the diaphragms recor s a range of blackening on a light sensitiveband, and several fixed mirrors for bending the ath of the licht.pointer for the purposeohtaining a more compact arrangement'nhicli isless sensitive to concussion and individnal oscillations.

10. Means for recordingr sound waves come prisingl in combination with adevice 'for col lecting the sound energy and for condensing the same, aplurality 'of small reflecting diaphragms attached atmone side only andexposed to the action of the condensed sound energy, a source of lightemitting a pencil of llti H faces on the other side, said diaphragmshavphi-agms in Succession, and from the last of ing different individualfrequencies, all 0f said diaphmgms t0 a desired point. said diaphragms4being'secured at one side In testimony whereof' we affix our signzi- 10only, and all having parallel axes of rotatures. l 5 tion, la source oflight, and means for di- JOSEPH MA SSOLLE.

recting a beam of light therefrom against DR. JOSEF ENGL. he reectingsurfaces of each of said dia- HANS VOGT.

